Electric credit card (Jun, 1970)

It’s like a smart card with out the smart! It seems like you could reproduce someone’s card by just looking at a picture of it…

Electric credit card

A printed-circuit credit card is the key to self-service gasoline in England. The gas pump unlocks when you insert your card in a slot to fill your tank. A data recorder recognizes your card, records your number and purchase on tape, and bills you later. The tiny circuit board doubles as a distinctive key fob.

Given that the ordinary credit card processing of the time relied upon the embossed numbers on the card and something like carbon paper to transfer them to a paper receipt, this may well have been an improvement in resistance to forgery. For that matter, reproducing house or car keys from a photograph is not at all unheard of.

Casandro says: July 17, 20129:47 pm

It’s just like a regular key. You can also read those out by taking a photograph.

Compared to biometrics this simply is gold as the key can be changed easily. Of course once integrated circuits became cheap you could simply build a card with a micro controller and sophisticated cryptography. Cryptography also didn’t quite exist back then.

vse says: July 18, 201211:38 am

Cryptography was alive and well since the late 30ies, especially in Briatin. I’m sure it was not forgotten by the 70ies. The idea behind that system is a different one: Lost or stolen keys could quite easily be declared invalid without changing the actual hardware. That’s not really viable with standard Yale lock cylinders…

JMyint says: July 18, 20121:57 pm

If I remember correctly these key cards were two sided. One side would have the code for the device, so that side would be the same for all users of a device. The other side would have the code for the individual user, therefore unique for that device. Each code was dependent on making 1 to 4 contacts on up to 8 sets of contacts for millions of combinations. The problems was these things were actually kind of difficult and messy to make and it could be expensive replacing a single key if lost, stolen or just worn out.

JMyint, I’ve probably mixed up my combinations and permutations, but… 1 of 8=8, 2 of 8=56, 3 of 8=56, and 4 of 8=70 for a grand total of 190 key codes. It must have been more than that.

Toronto says: July 18, 20126:31 pm

George – that’s eight 4-bit numbers, or 32 bits in all (4 billion plus.) But they probably didn’t allow all-zero combos, so 2.5 billion or so. Add some check-bit/crc and it’d down into the millions but still a lot.